Adds `crypto_sign_*`, `crypto_auth_*`, and `crypto_scalarmult_*` constants (#43274)
Adds `crypto_sign_*`, `crypto_auth_*`, and `crypto_scalarmult_*` constants (#43274)

These constants are documented here:
https://libsodium.gitbook.io/doc/public-key_cryptography/public-key_signatures#constants
https://libsodium.gitbook.io/doc/secret-key_cryptography/secret-key_authentication#constants
https://libsodium.gitbook.io/doc/advanced/scalar_multiplication#constants
georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,mcliment/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,markogresak/DefinitelyTyped